Help confirm my understanding of SR+ charging

[Zacster]

I've had my SR+ for almost a year now and I'm finally getting to the point where I can install the wall charger that I bought. I've had solar installed and the main panel replaced so I have open slots. My understanding is that the SR+ is limited to 32a charging, and that would mean I only need a 40a circuit? But if I want to future proof it a bit should I do a 50a circuit? The electrician is at my house right now and said to do 50 but he wouldn't do it today in any case because he is on the solar company payroll. With a 50a charger I would still only be able to use 32a and that would equate to about 30mrph? If I install a 30a circuit I would get about 24mrph? It'll cost the same either way I guess since the only difference is the wire gauge and breaker size, but it is the labor that costs the most.

Am I correct in this?

 

[jjrandorin]

SR+ maxes out at 32amp charging so if the goal is to max that out, you would want a 40 amp circuit.

If you plan on trying to "future proof" you would want to consider up to a 60amp circuit, which would give you 48amp charging, which is approximately 44 miles per hour, IF you buy a LR / Performance tesla or other EV.

See below for the chart. Approximately 30MPH with a 40 amp circuit / 32 amp charging. No faster on a SR+, but for future proofing, you can see increase below. If I was future proofing, AND there was readily available capacity, I would get a 60amp circuit even for the SR+. wont be any faster charging of that vehicle, but would be if you ever got a faster one.

I would only do that because I was already paying someone to install it already, and if going up to that 60amp circuit was simply adding the appropriate breaker and wire, not requiring any other panel changes etc.

 

[davewill]

Both the SR and the mobile adapter are limited to 32a, so if you're just installing a 14-50, you COULD just size it for 40a. If you don't mind spending more to "future proof", you can wire it for 60a, then use a 50a breaker with your 14-50 for now. Then in the future, you could upgrade to a wall connector and you'd just have to change the breaker to 60a, remove the outlet, and wire it in. You would then be good for up to 48a charging.

Personally, I would only wire it for 40a if there were significant cost reasons, like needing to upgrade the panel to go higher, or already having 40a sized wiring in the wall ready to use.

 

[driver7]

Facing a similar dilemma a few years ago we chose to "future proof" to a higher amp circuit. Figured eventually all EVs will accept higher current rates and it would be a time save not to have to rewire the circuit for our next car.

 

[Zacster]

My panel feed is 100a so maybe that would limit how high. The electrician just told me 50 is about all I should do so I'll do that.

 

[KenC]

Deciding between 8 additional amps is not much difference in the grand scheme of things.

 

[davewill]

My panel feed is 100a so maybe that would limit how high. The electrician just told me 50 is about all I should do so I'll do that.

Sounds entirely reasonable. If it won't cost much extra, it might be worth using the 60a sized wiring just in case, but with the small panel, it's unlikely that it would ever get used.

 

[Rocky_H]

Facing a similar dilemma a few years ago we chose to "future proof" to a higher amp circuit. Figured eventually all EVs will accept higher current rates and it would be a time save not to have to rewire the circuit for our next car.

Your thinking seems to be in the opposite direction to how the electric car manufacturers are going. They are going down in the power of the onboard chargers, not up.
Here are the highest amp levels Tesla used to offer for their cars:
80A
72A
48A
See how it has been continually going down? They are taking the perspective that the bigger expensive high power chargers being included in the cars is unnecessary expense there, and so are moving away from that. They are encouraging that if you need faster charging than that, just go to a Supercharger.
They also replaced their older wall connectors, which could provide 80A with the new ones, which can only provide 48A, showing that this is permanent.

So future proofing for maybe a 2nd or 3rd EV is a good idea, but thinking that individual cars are going to take higher and higher power probably isn't going to happen.

 

[3sr+buyer]

Basically, the usual choices, which must be on a dedicated circuit, are:

60A circuit -> 48A charging, hardwire only
50A circuit -> 40A charging, can be plug-in (14-50 or 6-50)
40A circuit -> 32A charging, can be plug-in (14-50 or 6-50)

Note that the SR+ and the included mobile connector EVSE (with appropriate adapter plug) are limited to 32A charging. Going to a larger circuit would only be if you anticipate getting a future EV and EVSE with higher power AC charging.

Plug-in EVSEs should not generally be used for frequent plugging and unplugging. However, plug-in can be more convenient if you need to replace the EVSE due to problems with the old one, or if you leave your mobile connector plugged in most of the time but take it with you for an occasional road trip.

 

[driver7]

Your thinking seems to be in the opposite direction to how the electric car manufacturers are going. They are going down in the power of the onboard chargers, not up.
Here are the highest amp levels Tesla used to offer for their cars:
80A
72A
48A
See how it has been continually going down? They are taking the perspective that the bigger expensive high power chargers being included in the cars is unnecessary expense there, and so are moving away from that. They are encouraging that if you need faster charging than that, just go to a Supercharger.
They also replaced their older wall connectors, which could provide 80A with the new ones, which can only provide 48A, showing that this is permanent.

So future proofing for maybe a 2nd or 3rd EV is a good idea, but thinking that individual cars are going to take higher and higher power probably isn't going to happen.

Thanks, I wasn’t aware of this trend.